that's very possible, if you put together the cause of the leaner AFR than it ought to be (i posted my thought on why it is happening on the first page) and the higher EGT values that are being created, we have a very very good situation for ping to occur sending the knock sensor on a timing retard frenzy and possibly a limp mode that would not allow full rpm use... i have to scower the manual to see if such a limp mode exists in the crossfire...